The invention relates to a constant velocity fixed joint.
DE 40 31 820 C2 describes a constant velocity fixed joint whose outer part comprises a first open end and a second open end. It comprises a cavity which is centered on the longitudinal outer part axis and which is open towards both open ends. Furthermore, in its inner face delimiting its cavity, the outer part comprises two types of outer running grooves which are arranged in a regular sequence around the longitudinal outer part axis in meridian planes relative to the latter. The first outer running grooves start from the first open end and extend towards the second open end. The second outer running grooves start from the second open end and extend towards the first open end. All outer running grooves extend in a curve-like and undercut-free way from the open end from which they start.
In the cavity of the outer part, there s arranged an inner part. The inner part comprises a longitudinal inner part axis and a spherical outer face which is provided with first and second inner running grooves which are arranged opposite the first and second outer running grooves and extend in meridian planes relative to the longitudinal inner part axis. The first inner running grooves are arranged opposite the first outer running grooves in such a way that they form pairs, with the first inner running grooves starting from the first open end and extending towards the second open end in a curve-like and undercut-free way.
The second inner running grooves are arranged opposite the second outer running grooves and form pairs therewith, with the second inner running grooves starting from the second open end and extending towards the first open end in a curve-like and undercut-free way.
Between the inner face of the outer part and the spherical outer face of the inner part there is arranged a cage whose spherical outer face comprises play relative to the inner face of the outer part. The cage is provided with a cylindrical bore which is held with play relative to the spherical outer face of the inner part. The cage is provided with radial apertures which are distributed in accordance with the pairs of inner running grooves and outer running grooves. The apertures form windows which guide the balls between the lateral guiding faces.
For torque transmitting purposes, the balls engage between the outer part and inner part into the outer running grooves and inner running grooves forming pairs. The centers of all balls are held in a plane which contains the window centers between the lateral guiding faces. The cage is centered entirely by the balls.
The above-described design is disadvantageous in the case of constant velocity joints rotating at high speeds such as they occur, for example, in the propeller shaft for transmitting a rotational movement in passenger cars from the front drive unit of same to the rear axle drive for rear wheel drive vehicles. In particular, vibrations occur to the displacement of the center of gravity of the cage, as a result of which a centrifugal force is generated.
DE 40 42 390 C2 proposes a constant velocity fixed joint whose design corresponds to that of the joint described in DE 40 31 820 C2. However, the cage is divided; it comprises a spherical inner face and lugs in the region of the lateral guiding faces, with said lugs increasing the size of the lateral guiding faces outwardly.